I finally finished up may gas gauge issue. I completely removed the harness for the tank selector switch and tied the gauge wire into the wire coming off of the sending unit. While I was at it I got all of my instrument panel lights working. I had the bend the tabs on the light plugs to make better contact on the printed circuit. I also replaced my speedometer since I broke the needle off of the original.
Since I was actually working on the truck I though I might as well rebuild the hydroboost. That seemed pretty straight forward. I already had the rebuild kit and a new master cylinder. Remove the brake lines and the two bolts on the master cylinder, easy enough. Remove the hydraulic lines from the hydroboost, piece of cake. Remove the 4 nuts holding the hydroboost to the fire wall in the engine bay, no big deal. Remove the last two nuts holding the hydroboost to the firewall from inside the cab, Holy hell, what where the idiot designers at GM thinking!!! After removing the AC duct I was at least able to see one of the nuts and the rod connected to the brake pedal. Unbolt the bracket on the pedal arm, remove the spring clip, and pull the rod off of the pin. Using a couple extensions and a swivel I was able to remove the visible nut. The other nut could not be seen or even felt. There are a bunch of electrical things in the way. I felt around and found a couple nuts that hold the brackets from the electrical stuff in place. It was easier at this point to remove the radio for better access. I was able to remove the electrical components and finally find a path to the last nut. A couple more extensions and the hydroboost was finally liberated from the truck. I found a few write ups for rebuilding the hydroboost so I won't go into great detail there. I didn't do a full rebuild, just replaced the the seal on the main shaft and the figure 8 seal between the halves. I mounted it back to the fire wall with the 5 nuts...yep, I left the one out in case I ever have to get this thing out again. I got the master cylinder bench blead and called it a night.
Wonderful progress pic.
Somewhere behind all of that stuff there is another nut.